Digital watermarking is a process for modifying physical or electronic media to embed a machine-readable code into the media. The media may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media signals such as images, audio signals, and video signals. However, it may also be applied to other types of media objects, including documents (e.g., through line, word or character shifting), software, multi-dimensional graphics models, and surface textures of objects.
Digital watermarking systems typically have two primary components: an encoder that embeds the watermark in a host media signal, and a decoder that detects and reads the embedded watermark from a signal suspected of containing a watermark (a suspect signal). The encoder embeds a watermark by altering the host media signal. The reading component analyzes a suspect signal to detect whether a watermark is present. In applications where the watermark encodes information, the reader extracts this information from the detected watermark.
Several particular watermarking techniques have been developed. The reader is presumed to be familiar with the literature in this field. Particular techniques for embedding and detecting imperceptible watermarks in media signals are detailed in the assignee's co-pending U.S. application Ser. No. 09/503,881 and U.S. Pat. No. 6,122,403, which are herein incorporated by reference.
As computing power increases, and transmission and storage of digital information becomes more inexpensive, the amount of digital content will continue to exponentially increase. Digital watermarking provides a way to embed an imperceptible watermark into digital content. In addition, digital watermarks can also be embedded into traditional media such as printed material. Watermarks provide a way to communicate additional information about the watermarked medium (also called cover medium) and therefore enhance the value of the embedded medium. This additional information can be used for a variety of applications—security, content protection, authentication, data hiding, content tracking, enabling a link between content and provider, to name just a few. Digital watermarking offers a unique advantage since this information is imperceptibly bound to the cover medium and travels with it.
The present invention enhances games, books and toys through digital watermarking.
Further features will become apparent with reference to the following detailed description and accompanying drawings.